The ability to separate gases and vapors increases in difficulty as the number of vapor components in the gas increases. Some gases, such as flue gas and other industrial gases, are extremely complex and separation of components such as water, acid gases like carbon dioxide, and heavy metals are made even more complex by the broad disparities in freezing points and chemical properties. Excellent progress has been made in removing these components, but no efficient and simple process has been developed before now that is capable of removing all of these components. A process requiring a minimum number of unit operations and requiring a minimum energy cost while still producing complete separation is required.
U.S. Pat. No. 6,962,061, to Wilding, et al., teaches an apparatus for the liquefaction of natural gas and related methods. An unpurified natural gas source is cooled in indirect-contact heat exchangers, expanded to create work, driving a compressor which compresses the process stream, which is then cooled. In this manner, solid carbon dioxide is produced in a liquid natural gas and separated in a hydrocyclone. The present disclosure differs from this disclosure in that the carrier gas is liquefied, only indirect-contact heat exchangers are used, compression and expansion are required, and the solid produced is not separated from the carrier gas, natural gas, but rather is solidified and remains in the natural gas and has to be further separated, rather than being separated by leaving the natural gas as a gas. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. No. 8,764,885, to Baxter, et al., teaches a system and method for separating condensable vapors from gases by desublimation and other solidification processes in a direct-contact heat exchanger. The present disclosure differs from this disclosure in that a single exchanger is used for desublimating exchange, rather than a plurality of desublimating exchangers, and all desublimation and solidification of all foulants occurs in the single desublimating exchanger rather than a portion of foulant in a plurality of exchangers. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. No. 5,467,722, to Meratla, teaches a method and apparatus for removing pollutants from flue gas. A flue gas is compressed and passed through a series of indirect-contact heat exchangers, removing water, nitrogen dioxide, sulfur dioxide, and carbon dioxide from the first through fourth stages, respectively. The present disclosure differs from this disclosure in that only indirect-contact heat exchangers are used and initial compression is required. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.